Best race for support artificer?

[Greywander]

Leaning Alchemist, even though I feel it's a little weaker than other subclasses (the Artillerist's protector turret makes a strong case for being the better support subclass), though I'm not sure this matters.

I'm considering a halfling with Bountiful Luck, as this seems like the only expressly support trait I can think of.

Otherwise, something like a high elf for the extra cantrip and swapping weapon proficiencies for more tools. Tool Expertise makes tool proficiencies really useful, with disguise kit, forgery kit, and herbalism kit offering some good utility. If I ever get a chance to craft items, especially common/uncommon magic items, artisan tools would also be useful. The free cantrip can let me pick up something like Mold Earth which isn't on the artificer list.

Mountain dwarf can get even more tool proficiencies, up to seven extra.

Variant human or custom lineage gives a feat. I can't think of a lot of good support feats, but Healer and Telekinetic (using the BA push/pull to reposition allies or pull them out of grapples) seem like good picks. I could take Inspiring Leader, but I'd lack the CHA to make it fully effective (especially at low levels), so I'll leave that for someone else.

Nothing else seems to stand out, but of course nothing is really a bad option. I could always pick a race for flavor.

[stoutstien]

Fey touched can be used to gain dissonant whispers which is a very good support spell if you have a few hard hitting allies or a swarm of weaker ones. Extra spells per day really helps half casters out to not fell so limited.

Healer is a good source of HP recovery. It maintains relevant for most of the game.

Ritual caster is always a good feat to pick up if you know you have to potential to find more spells. Later on you can copy your own ritual spells onto scrolls and back into the book fast and cheap.

The homunclus is a very flexible infusion to pick up. ranged bonus action damage is ok but having the ability to use the help action without interfering with your own is golden.

As far as races themselves, it really doesn't matter. The only thing artificers need is a good Int score so feel free to pick what you want to play not what you think will be more efficient.

[Quoz]

Take any small race through Tasha's Custom Lineage option. Use the feat it grants to take mounted combat. Craft a fancy hat that doubles as a saddle. You are now the Barbarian's familiar.

[kaervaak]

Custom Lineage for one of the many support feats would work well.

Inspiring Leader

Fey Touched (bless)

Chef

Ritual Caster

[Greywander]

I've been thinking about this some more, and there seem to be three "tiers" of races here, in terms of feat cost.

If I go with a halfling, I'd probably do the Mark of Hospitality for the free cantrip, though the expanded spell list isn't bad, either. But the whole point of going halfling is to grab Bountiful Luck, and I'd probably want to get it sooner rather than later. This sets me back a feat, and potentially pushes back maxing INT until 12th level.

Or I could go high elf for a free cantrip and several extra tool proficiencies. This one is feat-neutral.

Or I could go custom lineage/variant human and get an extra feat, and at 1st level. This does also come at the cost of slightly lower ability scores, but that just means I need to dump a dump stat from 10 to 8 (or not, if I use the free feat for a DEX or CON half feat like Chef).

The custom lineage is probably the strongest if I can get adequate downtime and cash to train all the tools I want (which is all of them). On the other hand, if we get a free feat at 1st level (which seems to be a fairly common houserule, but by no means something I should expect), then halfling actually looks viable. I could take Bountiful Luck as my free feat and still max INT by 8th level. In the end, high elf seems to be the most practical, though I'm not sure I'm sold on an elf for the character concept.

I'm warming up to a custom lineage, since I can get a good support feat without delaying INT progression (I could even max INT by 4th level if I get something like Fey Touched). If I do get a free feat at 1st level, then I can just grab two good support feats, or one of the other highly desirable feats. I mean, almost everybody loves Magic Initiate, Lucky, Alert, etc.

Interesting idea to get Bless via Fey Touched. Bless is always a great spell, I'm just not sure if there are other things I'd rather concentrate on, but it's definitely a nice option to have.